1. Field
These inventions relate to systems and methods for producing, shipping, distributing, and storing hydrogen.
2. Description of the Related Technology
Wind is the movement of air, which has mass, and when air is in motion, it contains kinetic energy. A wind energy system converts the kinetic energy of wind into mechanical or electrical energy that can be harnessed for practical use. Mechanical energy harnessed by windmills, for example, can be used for tasks such as pumping water for a well. Wind energy systems which harness the kinetic energy of the wind and convert it to electrical energy are generally referred to as wind turbines. As air flows past the rotor of a wind turbine, the rotor spins and drives the shaft of a gear box which in turn drives an electrical generator to produce electricity. The electricity generated by a wind turbine can be collected and fed into utility power lines, where it is mixed with electricity from other power plants and delivered to utility customers.
While it is known that energy derived from wind systems may be converted to energy of various forms, it is not common for electrical energy produced from wind turbines to be used in the production of hydrogen from the electrolysis of water. Hydrogen does not occur free in nature in useful quantities. It has to be made. One way to make hydrogen is to split the water molecule H2O to get the hydrogen. As this is typically an inefficient process, hydrogen is an energy transfer medium rather than a primary source of energy.
Hydrogen is the lightest of the elements with an atomic weight of 1.0. Liquid hydrogen has a density of 0.07 grams per cubic centimeter, whereas water has a density of 1.0 g/cc and gasoline about 0.75 g/cc. Advantageously, hydrogen stores approximately 2.6 times the energy per unit mass as gasoline. In addition, the burning of hydrogen produces no carbon dioxide (CO2) or any other green house gasses.
At present, hydrogen is mostly produced by steam methane reforming, and this will probably remain the most economical way as long as methane (natural gas) is available cheaply and in large quantities, and hydrogen is required only in small quantities. However, with dwindling supplies of methane, hydrogen will need to be obtained by splitting water H2O into hydrogen H2 and oxygen O2.
Typically, users of wind energy systems convert the wind energy into electrical energy and use the electrical energy directly. Infrastructure such as power lines can transport that electrical energy to the general population from wind turbine farms. At best, hydrogen is produced as a secondary energy source if excess electrical energy remains. Such hydrogen is usually stored and then burned to supplement electrical generation during times of low wind speeds due to a lack of infrastructure for transmission of hydrogen. However, as new infrastructure is adopted by society with an eye towards being environmentally friendly and less dependent on oil and gas resources, a significant market for hydrogen will emerge. Thus, it would be desirable to provide systems and methods for harnessing wind energy and converting such energy to hydrogen in a manner that would allow for the continuous and efficient production, storage, transportation, and distribution of hydrogen to the general public for consumption.